You don't need 5 flashes to use CLS. You just need one. The D3100 does not have a in-built flash commander, but it doesn't mean that the TS will not upgrade his body in the future. When I got a flash for my D5000, I did do my research, and chose the SB-600 over third party alternatives (Nissin Di622 Mk II, Yongnuo flashes, etc.). This is because I know I would upgrade my body in the future - which I did, to a D90, to help me take advantage of the CLS system. I got my 2nd hand D90 at $680 (you just have to hunt a bit and not be so fussy about the condition), a 18-55 VR on B&S goes for $100+, still under $1k. Stretch the budget a bit (not by much), and he can get a 2nd hand SB-600.
I am not a fanboy, I know that there are alternatives to the CLS system. But they are not equal alternatives. These triggers allow you to trigger your flashes. They don't allow you to change your flash power right from your camera. That makes a huge difference IMO. You may not realise it when you don't have it. But when you have it, you realise you can't live without it. Also, not everyone who swear by the CLS system have limited imagination. In fact, it is quite the contrary. In fact, some people who have limited imagination go for radio poppers just because they can't figure out ways to trigger their flash with CLS, because they don't know how to find places to bounce off the IR light, etc, and believe that they need radio triggers.
Blindly recommending lenses to people isn't very helpful. I made that mistake by listening to advice from people and reviews. I was told that the 55-200 is a very good lens, very sharp, value for money blah blah blah. I got it, and have used it less than 10 times. I have since sold it away. It is just a lens that does not suit my style of shooting. A 35/1.8 and a 55-200 combo may be perfect for you, but how do you know if that will suit his shooting style? What if he likes to shoot ultra wide? A Tokina 12-24 II or Sigma 10-20 may be a better idea. If he gets a 55-200, he may not use it at all.
My recommendation is always to use a 18-55 or 18-105 first, see what range you use the most, see if you need/want a faster aperture etc, then decide on what to buy.