Here's the numbers I use for the 260 000lbs, at which you'll be flying:
2 Eng:
Gear up, flap5, level flight: 60%
Gear down, flap 20, level flight: 65%
Gear down, flap 30 on the ILS/Vis final: 60%
Gear down, flap 30: 72% (75% if turning)
Since you won't be circling i.e. flying level with flap 30, you need to remember 60% & 65%.
1 Eng:
Gear up, flap 5, level flight: 80% (actually it's about 78% but set 80% and adjust)
Suggested technique for single eng ILS: On LOC, gear up, flap 5, 80%. Glideslope alive: gear down, flap 20 (watch the balloon when the flaps come down), set 70% and bug +5. The speed will drift slowly back and will pretty well coincide with G/S capture and bug+5. Slowly back to 65%, very little trim change due to lack of thrust lever movement and Robert will be your uncle. DON'T get slow. Err, if anything, very slightly fast (only talking 1 or 2 knots) as there is a lot of power required if you do get slow and that will destabilise your approach.
So, as you so correctly state, there are not really too many numbers you need. 2 eng: 60 & 65%. 1 eng: 80, 75 & 65%.