Many people are still entirely happy with friction front shifters, particularly with set-ups where you have to move your hand to the shifter anyhow. With only a double front, properly adjusted limit screws should allow you to pretty much toggle between end positions and be done with it.
Come to think of it, I don't think I've ever seen a 2-speed front shifter that's indexed unless it's a brifter.
And while I haven't tried it, I don't know if a front brifter intended for 8/9/10-speed rear system would be compatible with your setup. There may be some issues with chain/cage width, and possibly chainring spacing.
Looking at Google image search result, you've got a drop bar bike. This really limits the amount of indexed shifters(apart from brifters) that you can easily use anyhow.
Had it been flat bar, you'd have been able to pick up pretty much any indexed 3x7 front shifter and run with that. Using limit screws to dial out an unused position is no big deal.
You may be able to track down a front indexed thumb shifter for 3 rings, and bodge that one onto your stem or bar. I think I've handled one of those.
Shimano did produce a 6spd indexed stem shifter set for recreational 12 speed road bikes back in the day (1986). For your Maxima you'll need to see if any of your
existing componentry is compatible. If you're running Suntour derailleurs, then you'll need to change rear derailleur, chain and freewheel plus adding the indexed
shifters to gain RH 6s index capability.
6 speed indexed shifters used to be available in various quality levels. You can probably find one that is used or NOS.
If you have or can find a Suntour 'Ultra' 6 speed freewheel, it has the same spacing as Shimano 7 speed SIS gears, (source: Sheldon Brown) and so you could use a Shimano rear derailleur and 7 speed shifter. However, 7 speed has been extinct on all but entry-level bikes for years so you would have to find a used or NOS shifter for that, too.
You can also buy a new or used bike with indexed shifting already installed.
Best option is to sell the bike, and find one equipped the way you want. Without knowing more about your bike, you might need DT clamp on indexed shifters, new RD, new freewheel, new chain, new cables and housings. Cost will add up pretty quickly. Shimano made both 105 and 600 DT indexed shifters in six speed that were pretty nice. Light action DT shifters in six speed as well, that were fine. Shimano even made six speed indexed Dura Ace shifters (that will be a costly upgrade). You will have to hunt up a clamp (there is a guy on ebay selling them), as your stem shifter set up probably does not have DT shifter braze ons.
Thanks for all the detailed replies. I think I decided to just go ahead and buy the Shimano shifters for now and let see how that progresses from there. I do have another Maxima but that's 2X5 and that one has indexed shifters(for 5) and am very comfortable with them.