I am not personally familiar with the Achilles, but have read that they make very robust boats. If you are using your boat for diving, a heavy duty SIB would be quite important. Another option to consider is if you can find a used zodiac FC-470, or an FC-530 or an HD-Mark IV futura (same length as the FC 530). All 3 of these have the futura hull design, but are made of heavy duty hypalon. Since they are mil spec, they are quite pricey new, but every so often, a good deal (under 10,000 US) can be found on a slightly used one. You might also want to look into the various cat-hulled (or tunnel-hulled) SIBs that are out their (the round nosed types, rather than the zapcat/thundercat styles). These hull designs have amazingly good sea handling capabilities.
While I have never used the futura bench seat/console set up, I have seen it often and am very dubious of it. Sitting on a seat that is only 9" higher than the floor may be OK for calm conditions, but would be rather unpleasant when in large waves or a nasty chop. The futura Mark II Sport, comes with a jockey seat/console (not sure if these are still sold) which looks to have better ergonomics, but unfortunately it gobbles up alot of the deck space. Here is a link.
Zodiac offers Jockey seat/console systems for their military/commercial foldable boats of Mark III size and larger. Here are some links to these
Better still, IMO would be a jockey seat similar to the Ribpack version positioned neat the stern for tiller steering. A tiller will also give you much greater control when in challenging water conditions and is more fail proof. For diving, a tiller setup will provide you with much more gear storage space.