Intake gasket would be a good idea as the ones that come on the engines are just some thin junk paper of some sort.
While your at it.....if you have a dremel you may as well debur the inside of the intake tube, most have casting burs inside that will hinder air/fuel flow a bit.
I also use a 6mm nyloc nut as a jam nut (double nut) on the intake & exhaust studs plus loctite, having the first nut tight with the loctite on it and then a nyloc nut tightened down against the first one is the best way I have found to avoid those nuts vibrating loose, do this right and you can leave that 10mm wrench or socket at home, nothing ever comes loose on mine after i done this to them 963 miles later on one bike.
On that tensioner, I recommend after mounting it to frame that you make sure the roller is as far down as it will go so that as the chain stretches youcan raise it to remove the slack, also after you get it mounted in this position I recommend that you drill a small hole through the tensioner strap and into the Bike frame tube just in the one side of the tube though, no need to drill through both sides..... and then put a self tapping sheet metal screw in that holewith some loctite on it, this will eliminate the chance of the tensioner bracket from rotating inward and getting into the spokes, this could cause you a major headache.........! the stock tensioners actually hold up pretty good most of the time, the bike I'm pushing 1000 miles on still has the original tensioner and is still good as new.
Well, this is all I can think of right now and I think the other fella's here have covered just about everything else in a very good way ( better and quicker than I could have done it) but I do hope something I said here will help ya out and I wish you the best on the bike project and on the new job.....
Peace
I may be getting a little ahead of myself... i should just stick with the basics... i can replace the gaskets as a problem arrives and build a screamer in the meantime,,, this will give me more time to gather idea's, gain experience and pick your brains for a bit.....You guys are turning me into a peddlefile...ha