The Tower Hobby .46 engine bundled with the RTF version of the Tower Trainer .40 MkII is very powerful but also much more variable with regard to quality. Many folks own the Tower Hobbies .46 and love it, many others report various tuning and reliability problems with them. If you have a friend or instructor to help you who is good with engine tuning, it might be worth trying one.

As far as the Nexstar, or most other trainers, being able to land if the engine stops, virtually all trainer aircraft can be landed easily if the engine quits so long as they're at sufficient altitude and not in a weird aerobatic position when the engine shuts off.

When I flew my Nexstar, I joked that I knew it was time to come down and land when the engine stopped running. The Nexstar had a very gentle glide path and was easy to dead stick land. I used to fly my Nexstar out of gas all the time without any real worry of landing without power.

As for flight simulators, there are lots of good choices out there in the $60 to $200 price range. You can buy the ESky USB Flight Sim controller with FMS for $19.99 at http://www.raidentech.com for example, and then go to http://www.rcflightsim.com and download the Clear View flight sim demo and register it for only $39.99. The ESky USB controller is surprisingly good for the price, but the FMS flight sim is pretty rudimentary as a training tool. The ClearView flight sim is a really good simulator and works well with the ESky controller, so you'd have two flight sims and a dedicated sim controller all for $60 or so.

Another good flight sim on the lower end of the price scale is the Easy Fly 3 simulator from Ikarus:

http://www.easyfly3.com

Easy Fly 3 is built on the same physics and graphics engine as the more expensive Aerofly Professional Deluxe flight sim. It's more limited with regard to flying fields and model types, but it's a bargain at $99.99 including the USB Game Commander from the folks at Hobby Lobby:

http://www.hobby-lobby.com/flightsim.htm

As for full-blown, full-featured flight sims, you can select from AFD, RF G4, FS One, Reflex XTR, or Phoenix RC Flight Sim all in the $160 to $200 price range. By all reports each is very good. Most helicopter enthusiasts report a preference for Reflex XTR, so it might be worth seeking out if you plan on learning to fly helicopters in the future. All of the above sims model airplane and glider flight very well and are at least "good" with regard to helicopter flight modelling.

Good luck, and good shopping!