You will find the Varanus is a very nice all rounder for Sci build.
The extra Eng power makes EptS x 2 available and that frees up your Sci Team to be purely a debuff remover and thats a big plus point.
Its a very nice Boff loadout too, I find that 3 sci is a bit extreme and tends to force the builds in directions I never want to go in. But this has 2 and you get 7 sci powers and thats enough for a nice build no matter what you intentions are.
Its lhas the best points of the Fed DSSV (a personal fave of mine for strong sci support builds) and some things in common with the D'kyr too. Very nice ship in fact.
I have an Orion Engineer who ran a Bird of Prey up to top tier. While she does have the Heg'ta Bird of Prey (which is excellent), she has actually switched to the Kar'Fi Carrier. Totally different gameplay, but tremendous non-kilngon fun. As a Sci captain, you'll have more tricks to soften the targets up for your pets, but still deal a nasty punch yourself. Its also more nimble than you expect, especially if you've been saving surplus deuterium.
The Hegh BOP can make an excellent sci ship with great firepower to boot. I had my Orion sci in the Varanus for a while and hated it, felt like a gimped DSSV. I have an engie in the Karfi an have a lot of fun with it but it's a bit squishy for it's size (has only a little bit more hull than the Raptor at that tier for some odd reason). Overall I'd say Hegh BOP since it's really easy to tailor the BOff layout how you want it and is just a blast to fly.
How can you not love the looks of the Guramba? It's got tentacles!!! Tentacles!
Okay, setting that aside, I've read that the Kafir is a solid choice for science captains looking to do damage, plus it has an interesting update coming up to give it a solid survivability update to make it more competitive.