That frame could be anywhere from mid-80s to early 90s I think...measure the drop out spacing on the rear when you get it as I think that should impact what you put on it. There weren't really De Rosa models in this period...it's a De Rosa. You can call it a Professional, a Giro or just an SLX De Rosa (check the tube decal, looks SLX to me). My gut says that looks a little later than mid-80s.

$250 for a decent condition De Rosa frame is a very solid buy.

As far as parts...what are you going to do with it? Are you using it as a daily rider? A show off bike? If you're going to ride it, I'd go one of two directions...Dura Ace 7400 (especially if it measures 126mm) or something like Campagnolo 10sp centaur (especially if it measures 128 or 130mm). Maybe even an older campy 8sp gruppo - and those are usually available at pricing similar to nuovo/super record. I understand why everyone is saying period correct campy, but I'm not sure that I agree; the truth is that mid-80s campagnolo was truly the dark ages for campy and they barely survived it.

The best group available at the time was DA 7400 if it's mid/late 80s and most guys I knew who raced were changing over their drive trains to Shimano. C-record looks great, but its reputation as a crappy, heavy group is well deserved...I'd only use it for a show bike. NR and SR work fine, and are border line appropriate here, but they were regarded as dinosaurs by this era and I think someone buying this new in the mid-late 80s would have used DA 7400, or even a DA 7400/campy parts mix. I like the mixed groups with the DA 7400 drive train and Campy headset/seatpost/brake levers. Campy monoplanars ALWAYS look good (though I think the DA dual pivots were better brakes).

I don't think any of the older groups compare to a modern ergo group for ease of use, and Centaur looks fantastic on 80s steel. I would seriously consider making it a mean, modern hot rod, especially if it's 128 or 130mm spaced. You can use classic bits on the seatpost and headset for that touch of class.

If it's early 90s...and I think it might be...an 8sp record group would be both a period correct AND highly effective group. Pricing on those is also pretty reasonable and they were Campagnolo's triumphant return to relevancy, so I think they're also pretty cool.

Another possible way to go if it's mid 80s and you want to keep it period correct is Campagnolo Chorus...which is usually far cheaper than C-record and I think looks as good, or better for some parts.