Roadified MTBs can work, but they often have front forks too stiff, and with no mounting for front pannier racks.
Sporty cross-country racing bikes are often too agile and tight to handle luggage. Mid-range bikes often make better tourers than more expensive models.
MTB wheels are definately good on a tourer, thats why I recomended the Bruce Gorden.
Blackburn racks are the industry standard.
Ortleib are fine panniers, but in tropical damp conditions, can get manky inside from mildew.
Look for heavy duty fabric, good stiffening and rack mounting clips, and few zips,pockets or dividers (ie not too many features). One external pocket is sufficient.
Remember that touring is very hard on equipment, so you need tough bags. Check out the cheapest thin floppy bags in the shop for what not to get.