Nonstop, or connections? For nonstop services, you have UA or LH from EWR to MUC; while inbound you only have UA from TXL back to EWR.

Check Google Flights for options and prices. LH and UA non-stops are going to be at least $3,500 to over $4,000 RT depending on the day of travel.
You can save at least $1,000 by making a connection. Here is a random LOT option via Warsaw. Lie flat 787 for $2,556 RT.
https://goo.gl/flights/2EJqZ

Unless the non-stop flights come down in price or I decide to do premium economy it seems it has to be a connection for better costs. Doing a search I get the options of Icelandic, SAS and LOT for the $2500-$2700 price range in business class. Any stand out over the other as far as their business class goes? Looking at leaving on Aug 2 and return Aug 11.

Thank you

Presuming you mean Icelandair, its business class is inferior to the others, and is more like domestic first class than true international. Also note that would entail two relatively shorter flights which makes sleeping on the plane harder.

+1
I wouldn't even think about flying Icelandair when you have two much better lie flat options.
SAS' A330 is a 1-2-1 configuration while LOT's 788 is 2-2-2.
I'd go with either SAS or LOT based on the schedule and price. And since they are both Star Alliance airlines, you can credit your flights to Mileage Plus or another Star Alliance program.

You need to do some reading yourself ... look at the Trip Reports forum, for example, on what each airline offers ...
If you want to connect, then I'd suggest you want to spend the most time in a premium environment ... European short-haul business class is invariably economy seating with the middle seat blocked off.
With SAS and LOT, you will have lie-flat seats. You could also take LX (SWISS) via Zurich - with lie-flat seats.
As already noted, LH and UA offer lie-flat seats.
SAS is more out of the way and the RKV-MUC will be longer than ZRH-MUC and will be on SAS Plus, which is (again) basically economy seating.
You could take OS (Austrian) out of JFK ... and connect in Vienna
Iceland Air offers the option of a stopover, but their business class product does not have lie-flat seating.

Thank you all - the information gives me direction on where to go and look / research. Much appreciated.

If you're also wiling to consider flying out of JFK you can get a pretty good deal with TK which flies a widebody to/fro both MUC & TXL getting you lie-flat seats for all 4 segments & access to TK's rather nice lounge at IST.

Thank you Yoshi - EWR is 20 min from home while JFK is 50 miles away which on a good day will take me an hour and on a bad day two to three hours.

JFK-IST-MUC ?? Unless the OP is in favour of a significant detour this is not an option. Will add 5-6 travel hours compared to flights with SAS, OS or LOT

Anyway, you can't go wrong with SAS - even if you decide for SAS Plus (prem. economy) which is very decent.

Austrian Airlines offers nonstop flights EWR-VIE, though I am not sure if the service is daily. VIE is a good place to connect to MUC and from TXL.

After a lot of searching I am between these two - any opinions on which to take? Both business class. British Air and Delta - BA is $700 less and making me lean towards it. I have flown them in business before and it was fine. I haven't flown Delta business class. I was leaning towards SAS but the connection times were better with BA and Delta

Neither of those options are very exciting... if those are the sum total of your options.
BA has one of the world's worst Business Class products with 2-4-2 seating. Delta would be better with 1-2-1 seating, but it's still Delta.
But for $700, I'd probably suck it up and fly BA.

If you went with Delta, wouldn't you have to drive to JFK?

There is a Delta connection through Paris from / to EWR. Normally i try and book airfare in advance and have more choices. However with just a little over four months away many options which work for the dates, they are firm due to work commitment, everything was pricing at over $4000 for business class or had insane long connections. The Polish flight which I found at $2700 would get me in past the time I need to be in Munich on the first day. SAS had a good option going but coming home didn't work.