[Edited by deeppurple, 3/14/2012 5:39:56 PM]
You really shouldn't have a problem.
Are you using Windows 7? I had to convert all of my movies beforehand when I wanted them on DVD before I started using Windows 7, but the DVD Maker program that comes with 7 is fantastic and does it all for you - I just have a regular DVD player (~10 years old) and every DVD I've made with it works perfectly.
A DVD5 yes supports 120 mins of video if encoded to DVD standard, but you can put a low bitrate divx movie on a DVD that can be played on a DVD player to play for 999 hours if you wish.