Quick modifying question and hello!

[ashbudd7]

Firstly, it's probably about time to say hello! Finally got me a sierra a couepl of weeks ago after having the book (and the Ron champion before that!) for quite some time before realising I should just jump in and get on with it. It's pretty much stripped now and it's been quite some fun.
To the point now, I'm very strongly considering buying a pre-welded chassis from a builder. Now, I have a dohc and mt75 gearbox and by now I think you can guess where I'm headed... If I were to buy a chassis made for the type 9 would it be a reasonable enough job to cut out the parts that need changing and put new ones in to suit? I suppose the other option would be to change to the type 9 but then, iirc, I would need to change other parts and I'd like to keep it as simple as possible, and I think the 75 is lighter as well isn't it, so I'd prefer this 'box really. Just like some feedback/input from you more experienced and wiser guys really

Thanks in advance

Ash