Best book your break on Jumeira Beach area for the best of the hotel scene in Dubai. If you only have five days you will be stretched to get to much of Oman in but you will not be dissapointed even if its only a matter of days.
Getting into Oman from UAE is easy with your UAE Visa, if you drive down via Hatta (recommeded route from Dubai) stop at the Hatta Fort roundabout and get your visa there before proceeding otherwise it will be a 15 min backtrack when you get rejected at the new Omani border post. From Dubai safely to Muscat is about 4 hours plan on 5 if you drive like Miss Daisy.
One thing you will have to check is regards Hire Cars as previously they were not allowed across the border however this has changed recently I believe.
Nizwa is a beautiful historic town about 1 1/2 hours south and well worth a visit. Two very nice hotels down there, magnificant souq in the restored and famous Nizwa Fort.
The Musandam option is possibly better in your timeframe, a trip to Muscat and the interior is a hoiday in itself. I visited Khasab around December last year and stayed at the freshly opened Golden Tulip hotel. The fact it had just opened meant a little basic on the service side but the Omani staff were so friendly it didn't matter. The hotel is close to a 4 star in layout and facilities and fields the most spectacular view on the cliff of the Musandam Pennisula. There are Dhow trips and these can include diving etc. The drive from Dubai again about 5 hours and you can get your visa at the border.
Suggest getting your travel done in the first part of the trip then relax and enjoy the sights and sounds of Dubai on the last few days.
If you are thinking of travelling soon then remember it is Ramadan and your daily routine will be restricted by the customs of this period of the year, and if you are thinking about 13th-17th or so of November and you haven't booked you may be in strife as that is Eid Holidays and all the hotels will be close to booked out.
Hope that helps out. If you want some gen on the Dubai nightlife scene let me know, Dubai affords some "unique" establishments....
Have fun!
