Well everyone will advise you to go for a onza t-pro as it's a great starter bike, but thats only if you want 20" wheels. Your best bet is to look through www.tartybikes.co.uk then try and find them cheaper.
I started on a stock and was finding it really hard to progress, but when i rde my brothers mod i did everything with ease. So i went out and bought a mod.
Here's mine, can't remember what it is lol Haven't used it for ages as i killed it and had to replace al lthe servo's and it needs tunning. Oh, and it's not a nitro mt2.