Adventure Pilgrims Trekking offer Mt. Cho Oyu Expedition, the sixth highest mountain on the planet, has the best success rate... It is a technically straightforward climb with the best safety record for an 8000m mountain. And you don't have to trek weeks merely to get to base camp, so logistically it is easy.
Experience and fitness
Despite the relatively non-technical nature you MUST have some mountaineering experience and MUST have been to 6000m before (Denali/Aconcagua/Island Peak etc). You will need to climb on steep, near vertical ice for 25 metres and on a similar steep rock section, both with fixed ropes, traverse hard ice on a fixed rope and abseil down these sections several times. Don't underestimate the difficulty and strength of will required to climb at over 7000m.
Day 01 : Arrival Kathmandu (1350m.) transfer hotel
Day 02 : Kathmandu
Day 03 : Kathmandu
Day 04 : Drive to Kodari and transfer Zhangmu 2300m.
Day 05 : Drive Nylam 2750m.
Day 06 : Nylam rest for acclimatization
Day 07 : Drive Tingri 4340m.
Day 08 : Rest of day for acclimatized
Day 09 : Drive to Chinese Base Camp 5000m. Camping.
Day 10 : Chinese Base Camp
Day 11 : Prepared load to Yak for Advance Base Camp.
Day 12 : Base Camp - Middle camp with Yaks.
Day 13 : Middle Camp - Cho Oyu Advance Base Camp 5700m.
Day 14-39 : Limbing Period for Cho Oyu 8201m.
Day 40 : Advance Base camp - Chinese Base camp
Day 41 : Drive Base Camp - Zhangmu
Day 42 : Drive Zhangmu - Kathmandu
Day 43 : Kathmandu
Day 44 : Kathmandu