Planning an Express, questions!

[soma_hero]

Hey guys, first post around here. I've been reading a ton the last few days and I'm getting ready to move forward on an Express clone. I have a few questions though..

First, the chassis in the build materials list isn't shown on Mojomusic. There is a blank chassis that is 17X6.5X2.5. Is this big enough? I was also thinking about bending my own out of an old computer case but I've heard that steel chassis are not a good choice. is that legit?

Also, where can I get fiberboard material? I guess hoffman amps is the only place i've seen it.

For power transformers, I've got two sitting here. One has a 200-0-200, 400ma secondary, with 2 x 6.3v, 3A windings. The other transformer has 333-0-333, secondary with 6 and 5V taps for heaters/rectifier tube. Can I use either of these trannys or should I just go for the Toneslut 300-260-0-260-300?

And finally, I installed a modified Post-PIMV as sold by metroamps in my MIG50 and it works alrighty. What is the advantage of a VVR or an airbrake over installing either a pre or post PIMV?

Thanks all!
Michael