I'm up here now and so far I've checked these places out:
Sheffield 3 accomodation
Solly Houses at Central Place (Student Roost)
Brass Founders (Unite Students)
Liv Student Accomodation (that was the accomodation tour that the student ambassador at SHU took us too)
St Silas Apartments - flats inside a church. This is apparently unlikely to be available for January but they said someone may have left and to call around December .
4 porterbrook apartments on Broomhall Street. This is also unlikely to be available for January but they said similar about calling in December.
The last 3 are the closest to collegiate (between 9-13 minute walk to the heart of the campus, even shorter to Robert Winston building). However, I'm leaning towards Sheffield 3.
Liv Student Accom is nice, but only one flat of the whole building was postgrads. If sharing with undergrads/ having a studio is what you want, then this could be a really good option for you! Parking wise, the council is apparently going to sort out car parking next door, but currently the students rent out parking at the nearby Waitrose for £60 a month. They said that you have to book directly with Liv Students as on SHU's website it says there's no availability. In terms of the levels of "all-inclusive", Liv Student is the closest - you get breakfast free, and there's a gym onsite. You do have to pay for using the laundry room though -£2 for washing machine, £1 for dryer.
Brass Founders is also really nice, but there aren't any flats for postgrads.
Solly Houses is okay, and there is on street parking and inside the gates for the houses, there is 1 parking space allocated per house which you could request. For me there isn't enough storage, but if you're travelling light, it could be another option.
I'm leaning towards Sheffield 3. It's annoyingly the furthest walk from collegiate campus (30 minutes), and the parking spaces within the accommodation have been taken. However I had a walk around the accommodation and there's plenty of on-street parking. Researched on Sheffield council's website and it would cost £46.80 for the year for a parking permit for the roads surrounding the building. I'll probably call the council to double check that before making a final decision. I looked at both the studio and ensuite - silver and there's a good deal of space in the room. The laundry room costs £3.20 per wash and £1.70 to dry.
I'm going to check out Gatecrasher apartments and Charlotte court and get back to you. I will probably apply for charlotte court regardless as another option at the very least.
Hope that (very wordy message) helps!