replacing a shifter

[amorphous]

My 3 speed Sora front derailleur shifter is kaput, and needs replaced.
(I think the spring is gone)

Do I need to replace it like for like, or can I use any similar Shimano 3 speed shifters (altus, acera)

 

[cyberknight]

I would replace it with a road one, mtb have a different cable pull ratio.

 

[jefmcg]

My 3 speed Sora front derailleur shifter is kaput, and needs replaced.
(I think the spring is gone)

+1 to @cyberknight

Also, if you aren't replacing like-for-like, you will probably want to replace both shifters, as the new hoods will be a different shape so the bike will look and feel strange if you don't replace both.

As you have broken the front shifter, have a look on ebay, you may get a bargain. The rear shifter tends to be used much more, and thus fails more often so people will be more likely to be selling what you need. When I broke my Tiagra rear shifter, I could only find front ones for sale. FWIW, I happily easily upgraded from 2/10 Tiagra to 2/10 105s without issue.

 

[Milkfloat]

I would replace it with a road one, mtb have a different cable pull ratio.

Not at Sora level, which will be maximum 9 speed. Personally - I would pick up a replacement Sora shifter or a pair from eBay.

 

[lpretro1]

The Shimano Claris are 9 speed - but likely you can only buy in pairs

 

[Ajax Bay]

Take care that you choose an STI which is compatible with your triple FD. Your choice is whether to buy a pair or just the left one. Styles keep changing so you can match your RH Sora STI but the supply is limited. Agree with @cyberknight : plenty of pairs of STIs on e-bay and some just LH STIs. I 'won' a pair of Tiagra 4400 STIs last month.