The sewing revolution is another hany item you could use to get your placements correct. Here is info on it.
http://www.thesewingrevolution.co...
ok so what size exactly is your hoop. another thought is pick out all the designs you want to use and print them out then you could cut them out around design and then place them where they fit or you think they would all look good together. This you do on a large piece of plain paper or even tempory piece of fabric. Play with it till it works then you mark your fabric in the wash away pen as to where each design goes and hoop fabric to each design seperately. Now it will take some time and effort but it is do-able... if you are unsure of what I mean, ask me some more I may be able to help out more, or someone else will jump in for me...
I may depend on how big your hoop is and what you can fit it in...You can merge pattens or combine like daisy530 says.
I have a cloth setter with my janome and it helps place designs in the right places