Sanity check re engine swap options/planning

Hi all,

very recent owner of a 70 Dart Swinger with a stock slant six/auto tranny (has issues but does crank) and looking to take the opportunity to upgrade to a V8 so I'm doing some research and planning. I'll also be looking to upgrade the brakes (disc up front at a minimum) and suspension.

Generally speaking, looking for an end result that is street drive-able on decent pump gas but improved performance over stock, maybe in the 350-400 HP range if possible. I'm not worried about show car looks or numbers matching etc. Leaning towards a more modern engine but not 100% settled with bonus points for more straightforward projects (I'll have help from people more experienced) as opposed to something requiring a lot of additional modifications above what other swaps would need. I'd like to be around 2-3k if possible though that's not an absolute set in stone number.

I've come across a couple different engine options (on this forum and a few other pages) and I know that there is good support for a 5.9 magnum swap. My understanding is that a Magnum swap requires less modifications than a more modern hemi and that the Magnums have a considerably lower starting price. My first question would be if there are any obvious options I'm missing beyond these two or other considerations I need to immediately take into account before thinking about what engine path to take.

Thanks all, really appreciate any and all advice/thoughts/comments/opinions.