Yes, do it. There is no reason NOT to do it.
The reamer is available from any tool house. You can buy the tubing from the same place. I use MSC, but I've been buying tooling from them since probably the early 1990's but any good tool supply company will have the reamer.
Let me give you a tip.
It is not required (and is probably a really BAD idea) to press the tube in. What I'm saying is...buy the tubing FIRST and measure the O.D. and then order the reamer so that you have .0010-.0000 press fit.
I always lightly polish the O.D. of the tube before I install it and it can actually even technically fall in if you want it to and it won't matter. It can't be like socks on a rooster, but you don't need to beat your guts out to get it in. Once you peen the tube it can never come out so it can slip in, and I slip fit all mine.
You also don't need to angle cut the tube. Just cut them square and forget it. Make sure they go past the last lifter bore from each and and that's fine.
I made my own peen tool, but you can use an old lifter and round off the edges. It ain't rocket surgery. Don't forget to redrill the feed galley passages from the lifter bank to the mains. Drill them all to 9/32 and I know guys who love to go .312, but the hole that feeds those passages is still the same size, so making the feeds much bigger than .287ish (9/32) is not really needed.
Once you get that done, you hone the lifter bores LIGHTLY and VERIFY that the lifter will fall on its own down that bore. Even after peening the tube will make the bore tight, and if you don't fix it, you WILL fail a cam. I take a paper roll and lightly polish the tube where it breaks through the lifter bore after peening. Then a light light hone, verify the lifter will fall down the bore and you are golden.
Do it. There is no reason.
