welocme to the forum smiler78!
well i'm not really expert into this.. in our case my husband just showed small amount savings in his bank statements then he explained in his letter of support the reason why.
i guess as long as u have a good monthly income and will explain everything in the letter on how u will support ur fiancee, will be fine.. i'm not so sure about it though.
btw, we applied for spouse visa and it's approved
chryss