Need NoCatSplash setup and working on DD-WRT v24-sp2 (10/10/09) std (SVN revision 13064).
I'll provide webhost for html file.
3 freelancers are bidding on average $157 for this job
I've complete such projects before. I've got few Custom Captive Portals, maybe you will be interested into those, one of which has a method of payment through PayPal.