I'd recommend against buying a complete armorer's kit anywhere, as you'll get a lot of unnecessary stuff with it, and pay a lot to boot. Some of what I bought isn't critical, but I felt a need to get it.
www.bushmaster.comBushmaster handguard removal tool -- #HGD-Tool -- $19.95
Bushmaster receiver push pin tool -- #IMP-1 -- $6.95
Bushmaster action clamp -- #OM-003 -- $38.95
Bushmaster firing pin protrusion gauge -- #MMT-0005 -- $14.95
www.brownells.comBrownells Bench Block (round, grooved) -- #498-100-100 -- $12.50
Brownells AR-15 Front Sight Bench Block -- #080-000-252 -- $34.97
Brownells needle oilers (quantity 3) -- #084-038-203 --$6.67
Kroil (8-ounce can) -- #471-100-008 -- $8.90
Gas tube wrench-- #133-100-015 -- $24.95
"Field Gauge" -- #319-418-033 -- $14.94
doityourself.comDasco 4 1/2" X 1/16" pin punch -- #6476659 -- $3.69
Dasco 5 1/2" X 3/32" pin punch -- #6472732 -- $3.89
www1.mscdirect.com/cgi/nnsrhmProto 4 1/4" X 3/32" Tip Super-Duty Roll Pin Punch -- #J49332 -- $4.96
Proto 4 1/4" X 1/8" Tip Super-Duty Roll Pin Punch -- #J49018 -- $5.43
Stanley 3/32" Square Nail Set -- #58-113 -- $2.55
Stanley 5 oz. Magnetic Tack Hammer -- #54-304 -- $11.03
www.olyarms.comOlympic Arms armorer's wrench -- #H28B -- $27
www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=239Pittsburgh Tools 1/2" Torque Wrench-- #239-3VGA -- $9.99
www.plastixplustx.com/ar15/ar15.htmlMaintenance stand
I also bought a set of snap ring pliers, a small set of needlenose pliers, a 16-ounce ballpeen hammer, a vise, moly lube, and painter's tape. I think I've remembered everything.