That kit will work but I don't know how good the ring/cogs are.
I just converted an old Trek hardtail. I bought my parts from bikeman.com SS store (great store- thanks Bikeman! :thumbsup: )
I didn't go super cheap. I highly recommend the SS specific rings/cogs made by Surly. Good quality, seem indestructable, and the cogs have wide bases which won't ruin your freehub shell.
I used:
Surly Singleator (new design- works excellently so far)
Surly 32 x 104mm 4 bolt SS chainring
Surly 20t SS cog
Spot spacer kit (a little bling, but Surly kit was unavailable)
Sram PC-58 8 speed chain
To do the conversion, you need the following tools:
Crank puller
Chainwhip
Cassette lockring tool and an adjustable wrench
Allen wrenches (a bike-specific multitool will do)
Short breaker bar with 8mm allen (handy for crank bolt)
Chain tool (for shortening chain)
18mm cone wrench (for Singleator)
Small flat screwdriver
Mechanical aptitude (not much)
Beer
Run the Singleator in push-up mode- it works very well
if you follow the directions. If you don't have an 18mm cone wrench, beg, borrow or steal one or try my method and make one from sheetmetal (not shop quality, but it works :thumbsup

. Get your chainline as close to perfect as you can, and shorten the chain as much as possible. Its not hard. Good luck!