That is exactly how I started, with a Juwel Rekord 60 (54L). Then I took the hood off and added T5 lighting and CO2, then removed the internal filter and added an external.
I massively urge you not to go this way, there are several reasons not to. Firstly, it's a lot more work and faffing about, then if you look at it all, it really is not cost effective as you are buying a load of stuff that you won't actually use in the end. Also a very important point is that the dimensions of these type of tanks often don't work very well as planted aquariums I found. For example the Rekord 60 is 60x30x30cm. With the substrate that really is not enough space for stems at the back IMO, a 60cm tank should be taller. The ADA tanks or similar are perfect dimensions in each size, they are great. Also the square cut glass is much nicer and if you do go ADA, really there is nothing better in terms of build quality and glass clearness. And not to mention that black silicone on the Juwels, yuck! Ultimately it's a personal choice but I find these tanks to be the best for planted aquariums, look the best, and be easily adaptable to many arrangements in terms of planting AND hardware setup. Can't recommend them strongly enough.
Snowballs are the same as cherry shrimp, just bred for a different colour. I kept Sakuras (selectively bred cherries, for brighter red) and they were great. Yes I bought the tank from TGM. You make a good point about getting snails and allowing more room for other micro fish. I have kept ottos before in my 60cm, and they do sometimes swim incredibly fast, so perhaps this tank is too small for them to be happy. Also I think they like to be kept in a least a pair if not a group.
Paul