Men are cheap. I mean, you can get like 10,000 dudes carrying lasguns as a Common level acquisition. It's their level of training that makes them more difficult to find. The better trained your soldiers are, the more experience the acquisition.
Basically, the cost of something goes up the rarer it is, goes down the fewer of the idea you want, and goes up based on the quality of the item.
So, acquiring something Best Quality is a -30 mod. Acquiring on one is +30. A Scare availablity item is +0. So, acquiring only one of a Scare item that is Best Quality, has a total Acquisition modifier of +0. To acquire the item, you have to roll a d100 under your total Profit Factor. Your current Profit Factor is 75.
As for suggestions, as captain you'll want status symbols. In the Imperium of mankind, that means a bolt gun of some kind. Some weapons do more damage and some are better to shot but bolt guns are to 40K humans what katanas are to gamer nerds. A Thermal Lance might be able to pierce three bulkheads on a cruisers and still turn an asshole in guard flak plate into ash when it finally hits him but to the average citizen it just looks like a big piece of equipment. A boltgun, on the other hand, is a nearly universally understood symbol. It's the Desert Eagle, it's the .45, it's the AK-47, it's that one gun that anybody who's ever seen a movie or heard a story knows about and if you've got one that puts you a step up on somebody who doesn't. Any major figure in space affairs wants a boltgun, even if it's just a showy pistol.
There's also the matter of expanding your current equipment. Powered Armor requires, surprise!, power. A normal battery, which you curretly have, only lasts for a maximum of five hours before the suit will power down. If you want longer, you need a military grade battery. Luckily, Rogue Traders can get the good shit... but they have to pay for it. Getting a military battery, which would allow from 24 hours of continued use AND have an emergency backup built in, would be a whole acquisition on its own but its the only way to go if you want to be able to pimp walk your way across the planet you plan to crush.