It's definitely big enough to provide good cooling, lol
As far as where the input/outputs are, that is strictly an issue of how easily you can hook things up in your system. If it were me and I used that core, I would cut off the ins/outs where they make the 90 degree bend.
Should you get it? Hmmm... from the picture it looks
well used, not new. Being used you would have possible issues of a) leaks b) blockage and c) all kinds of cr@p inside it.
Have you tried checking out local radiator repair shops? You might be able to find a good heater core at one of them that isn't too expensive. Plus it would be pressure tested, cleaned, and come with some kind of guarantee
