Phil,
They were bantering against themselves, not against you. It's a regular contest between a few forum members, and just something to get used to. and nowhere near as bad as you will find on many forums.
At no point did I see them try to drag you into it or insult you, so please don't take it personally.
The VQ35DE engine is pretty solid up to around 400bhp (which is where the associated torque generated kills the internals.
360 on a stock motor is easily achievable with the right modifications. The cheapest route would be for a S/C set up which could be dont for a little over £6k if you are not stingy. But it can be done for less if you do the work yourself and sourxe the best price items.
A TT kit would be around £8-10k depending.
Vortec, GTM, and HKS are the main s/c kits. GTM also do a turn key TT kit which is supposed to be pretty good.
My recommendation would be to call Abbey Motorsport and have a chat with Mark there about exactly what it is you want from the car. He will be able to point you in the right direction, and get you prices for kits and fitting.