Tiger barbs nice choice. They are very active preferring longer tanks. 20 long instead of 20 high as an example. Mine never hurt any of the plants I put in with them other than a leaf nip or two but never anything substantial.
Like Peter said plants, decoration, and substrate are all up to what you like.
With tiger barbs you just have to watch your fish stocking. They can be fin nippers. At first mine were in a 20 long with a rainbow shark. When I moved them to my 40 gal. I added some 3 spot gourami. Both could hold their own with the tigers.
Hope this helps.
Look for plants for a low tech setup. Java fern, anubias and vallisneria would be great ones to try. Some plants need special lights and co2 which can get expensive. Java fern and anubias feed thru the leaves so substrate doesn't matter, they like to be tied to wood or something, not planted in the gravel. I think vallisneria would grow in about any substrate but I agree with Peter, use root tabs. Post a pic when you get your new tank done, would love to see it.
I have a 30 gallon which I have anubias, Java fern, and val. I have in there Black, albino, and green tiger barbs. I have found that the bigger the school the less the tail nips. Also in the tank is a red tailed shark, clown loaches, bleeding heart tetras, skirted tetras, mollies, and cory cats. All get along great. I also would recommend getting older bigger Barbs if keeping them with other differ fish.. I have found the older they are the less aggressive as well... I hope this helps.... Post pics would love to see what you go with .
Looks good. NIce plant selection too.
Otocinclus did well with my tiger barbs. For the first day the barbs were curious and nipped them to see what they were but after that left them alone for the most part.
As long as the otos have a place to retreat to they should do fine.
Cherry shrimp make nice tiger barb snacks. You could try adding some adult ghost shrimp; they are much larger than cherries and less expensive.