If Liverpool's Bouzanis hasn't yet moved, he should be open to the offer of first team football. Joáo Carlos of Athletico Paranaense will be championship quality by midway through second season and will only get better with first team football and good coaching. At this stage he's also more likely to get a WP. Corradini has already been covered but he can be a bit shaky until 3rd season onwards
imo.
In midfield, you might want to try loaning Sidwell or Flamini if they haven't moved yet. I don't think either are usually happy with championship, but you are an ex-
prem club which could help. Just sift through the reserves of the
prem clubs and nab whoever looks good.
Up front I imagine Stancu is already gone, so I'd reccomend Fraizer Campbell (decent
prem backup too), who you can easily get on loan if not perm, and Martin Paterson of Scunthorpe (probably not
prem quality). Paterson doesn't look great, but defenders in the championship are slow and his pace is staggering. I think he broke 40 goals in a season last time I played him in the championship, moving from 5th place backup striker to 1st choice in a matter of weeks.
Get a parent club, steal their youth talent on loan, then buy them when you get promoted. If all you need are three players, it's better to loan them in and get
prem-quality when you're back there than get championship quality who you'll need to sell when you get promoted.