HPV's seat bracket arrangement means that boom length is unaffected by seat angle (it pivots around your hip joint), so get the boom length right first.
Stick some tape on the boom as a reference point for rotation (and indeed length, if there isn't a greasy mark). It can be insanely tricky to get that spot on on a bike, particularly if you're tweaking at the roadside.
Bar adjustment presumably comes once you've worked out what the seat angle should be. If you're new to recumbents you'll probably find it easier to control if you start off with the seat fairly upright, and re-adjust once you've got the hang of the bike.
Not sure how much handlebar adjustment there is on that one, but on my hamster-barred Baron I spent a lot of time trying to find the optimum compromise between being able to see the road ahead (it's a bit more reclined than a Speedmachine) comfortable wrist angle and leg/boob clearance. That included tweaking the position of the brake levers on the bars.
The golden rule for recumbent ergonomics is to adjust for the position on the seat that you gravitate to after you've been riding for a few miles, not the position you start off in when you get on the bike.
