Welcome, Freddie! It's almost certainly a 189 model -- there are some with the kitchen in front, and some with the kitchen on the side (I think). Click on some Youtube tours -- you will recognize your floorplan pretty quickly.
When it comes to batteries, there are a lot of options. The answer depends on whether you plan to stay in RV parks or plan to dry camp or boondock, and for how long. If you will be in RV parks, a group 24 or 27 might be enough. They are easier to lift than the bigger batteries. And yes, get a battery tender. I like the Battery Minder Plus -- it pulses to avoid "sulphation" of the plates inside the battery.
Personally, I have two group 31 batteries. We do a lot of back-country boondocking. The batteries are heavy but they hold a lot of juice.
Is this your first RV? Where are you located, and where are you going to travel?
Keep asking questions! Us old-timers love to answer them -- it is fun to help newbies avoid the mistakes we made long ago.