Regardless, a general 'cookie cutter' equipment you can go on is:
6 beam arrays, 3 in front and 3 in back, along with a torpedo in the front, and then a torpedo or mine in the back. Plasma energy weapons are usually cheap enough to buy, and Photons or Quantum torpedoes are generally good choices
Resilient or Covariant shield array, Positron Deflector, Hyper-Impulse Engines
Consoles: Put Neutronium consoles if you can afford em, otherwise, at least one Monotanium and then other consoles to resist whatever you are going to fight (plasma resist for fighting Borg for example), Tac consoles to match your weapon energy type, and sci consoles to boost shield capacity, healing, and regen.
All that together might seem like a lot, but there is HEAPS of even white, green, and blue Mk XI of all that stuff on the exchange, which if you are just willing to be thrifty and not go with the fancier stuff, you can build a ship on a budget.
As for BOFF slots, again, as above: Gotta know if it's the normal Sovy, or the Regent refit.