I have the scs 225's in my boat. They are without a doubt the best batteries i have ever used period. The ones i have are a group 31 size, i had to swap the battery trays out to get them to fit. The scs 200 is a group 27 size and will fit right in the stock trays that the nitro comes with. The scs 200 is a very good battery for its size, it had a greater capacity then most other group 27 batteries, the same can also be said for the scs 225's that i have. I would get the scs series for sure for trolling, its what its designed for. The tm series is a dual purpose and has less capicity(i run a 27tm for my starting battery)
To give you an idea on the performance ill describe what i fished in my tournament on sat. I fished in a 20-25mph wind all day (7am to 4pm)with my 74# minnkota on anywhere from 70%power all the way to high. i almost never took my foot off it when i was fishing bacause of the wind and boat wakes. After all that i still had full power at the end of the day and when i went to the hotel room to charge up they were fully charged in like 3 hours, i hardly even ran them down. These batteries have seen a season and a half of tough use and still work like new. yes thay are a little more money then walmart batteries but worth every penny in my opinion.