I'm not going to make specific recommendation here. But some info can go a long way.
In most cases BTU is BTU. Everything depends on how fast do you want to heat your pool and at what temp you want to keep it.
Heat pumps are amazing, but is the the exception to BTU being BTU...
This is the spec page for Pentair heat pumps you are going to notice that there are 3 columns for BTU. On each header for a BTU column you will have something like 80 80 80 ... the first 80 is air temp, the second 80 is relative humidity and the third 80 is water temp... same applies to the other two columns. The higher the air temp and relative humidity the better a heat pump performs while the lower the air temp and relative humidity the worst it performs. In early-mid May you should not expect more than 86k BTU from a 140k BTU heat pump. Many heat pumps models allow usage of multiple units in parallel to increase the total BTU of the system, but each one will need a branch circuit that will quickly add up. Also heat pump perform really poorly when air temp is below 50F and only models with anti-freeze can operate below 42F.
This year I was able to get my pool to 89F in later May with an undersized heat pump and solar cover. It took about 4 days for water temp to go from 49F to 89F running 24/7 with air temps between 55F-75F and RH close to 80%. But after that it runs about 3 hours per day to maintain my water temp around 89F.
Also a heat pump as a backup of a solar heating may be less than ideal as a cloudy chilling day will affect both.