The best way to book a Kilimanjaro climb is to go to Moshi and then personally visit the offices of the companies you're considering. You can ask all the questions you want then. All of them are flexible. Say what you want, and they'll arrange it, from a budget climb to the most fancy. That includes safety equipment, better tents, better food, warm clothes, group size. Whatever is on your list. You can also effectively negotiate price. Very few of them have websites. Most that do are like the one you're considering: heavily marketed by foreigners with correspondingly higher prices. Anyone who pays $2,000 (not including tips) for a Kili climb is paying too much, IMO, unless you're taking an unusual or long route, such as the Western Breach with a campsite in the crater. I don't know their current prices, but the Marangu Hotel (among others) is honest and arranges safe climbs. Plus, their hotel is beautiful and comfortable without being ostentatious.

Have you looked closely at the fine print of the company you are considering? Their well trained guides with loads of experience and a high degree of safety training rarely lead the climbs personally. This illustrates the problem with climb websites. If you're not careful, you'll pay way too much or pay for things that you don't actually get.

I know what I'm talking about because I've lived in Moshi 5 months out of the last 2 years.