The rigidity issues arise because a camera exposure is normally on the order of less than one second and enlarger exposures are typically on the order of tens of seconds (any potential for movement is amplified by the time alone).
If you have the capability of exposing 8X10 negatives, you have two choices the first is to do contact prints only. The second is to buy an 8X10 enlarger. The third choice would be to obtain an 8X10 to 4X5 reducing back for your camera and expose 4X5 film after which you can buy a 4X5 enlarger so that those negatives could be enlarged (4X5 enlargers are several magnitudes less expensive than 8X10 enlargers).
Hope that this helps.