If you can find a second hand Keycool 84, that would be best. Closest to standard layout of all the 84 key boards and good quality for the price.
I recommend rather getting a TKL or 60% if you want to replace keycaps, though, since ALL the 75% boards have non-standard layout. Poker II is programmable so you can make your own Fn layout if you like. It's pretty easy to get used to using the F keys, arrows and edit keys on Fn layer.
If you NEED arrow keys and want a really compact board, then the Leopold FC660M is a good layout. It "only" has a 2.25x right Shift (and 1x left Win key) as differences from standard layout keycaps. You can use a second left shift for the right shift as they're identical in size.