sparkling gourami's should be fine with the shrimp especially in that big tank. they might eat some babies now and then but your colony should still grow. id prob get like 6-12 of them.
also could do some ottos, pygmy corys.
if you want to do small fish go for it, i completely understand. its deff not the best use of space but if its what you want. honestly a shorter tank like a 75g would be better sense you have no need for height.
8g Fluval 1M CT Betta
125g 5 Blood parrots, 1 Green Severum, 8 Dension Barbs, 10 Yoyo Loaches, 1 RTS
75g Angelfish, 3 EBGR, 4 Siames Alage Eaters, 12 Harlequin Rasboars, 1 BN Pleco, 1 Swordtail
33g long cherry shrimp, 8 pygmy corys, 5 ottos
15g 2 GBR