Well the way I see it, you aren't gonna just sign an all-star squad for next season. To me it just can't happen. I think you''ll need to make some 2-year deals on some good young players mixed with a few experienced ones to gradually develop a squad that only needs tweaking from time to time. The improvement will be there, just much more gradual than the "we will win the league next year" attitude which could well backfire.
You already have some good quality players, such as Theo Fages who I think is awesome, and obviously Gleeson in the centres... You can build around players like this rather than pulling on people from all over and jumbling them together.
Elliot Whitehead was a fantastic signing IMO