Shifters - Rapid Fire, rear - Shimano, 9 Speed index
Trigger shifters are ugly and take up a lot of room on handlebars, but they're good for people with small hands or if you're building a bike for someone who can't stand to mess a shift up now and then, which, with friction shifting is bound to happen on bumpy trails occasionally.
If you use these it'll help if you know how to use barrel adjusters because when you're using indexing the window of correct cable tension gets a lot smaller. Put it in the small cog in back, click the shifter once and if it doesn't jump up, your tension is too loose. If it jumps passed the next cog, your tension is too tight. Work your way up the cassette using this method until it works for every shift.
Also, make sure your derailleur hanger is straight otherwise these'll be a pain.
If you're putting these on upright bars, all of them will work well except perhaps for the Albatross, which has a smaller grip area than the rest of our uprights.
We're only selling them for rear derailleurs, because front indexing is the worst. If the bike industry wasn't so scared of alienating new riders bikes would come with a trigger or brifter (if they have to be indexed) for the rear, and a cheap friction shifter for the front. Use a Sunrace thumbie for the front, it's the best for front derailleurs.
Alivios are cheaper than Deores, but both are 100% functional
Alivio M4000 (grey)
discontinued by Shimano, sorry - Deore M590 ISLM590RA