Most pre-recorded DVD's these days (if not all) are Dual-Layer and can hold about 9Gb of data. Therefore standard DVD players all read them.
Most cheap blank DVD's for home use are only single layer, but dual layer blanks can be bought (but are more expensive). The important thing is - Can your DVD Writer write to a Dual layer disc (older ones genreally can't) ?
If not there are lots of software packages (Nero, DVDShrink etc.) that will shrink the content down - but there will always be some loss of quality. Sometimes that can be can be got around to some extent by the software you use to do the shrinking - but from my experience, the results can be very variable.
Blank DVD's are so cheap you may as well try a few experiments to see if the results are acceptable, and if not invest in some dual-layer ones.