Bike or rower for damaged knees and herniated disks

Happyme2009

Hi everybody. I was thinking that I would like to purchase a cardio machine.
Problem is my house is very tiny so I have no space.
Also I have herniated disks in my back from an accident ( but they rarely bother me if I am careful what exercises I do ) and knee problems ( knees grinding, deviated round bone, beginning of artritis and cartilage issues). Again, if I am careful, I'm ok;
My favorite cardio in the gym is the cross trainer ( sort of an elliptical ). I cannot buy one of those because I have no space in the house. For outside exercise, I walk. Never run.
I was considering purchasing , from Costco, and they are both on sale until tomorrow, either the rower ( First Degree Newport Rower, sale $670 +tax on sale ), or the ETerraBR890 indoor cycle) ( on sale for $400+tax)
Mind you, money is an issue too.. so the bike is cheaper than the rower.
What should I do?
Which one would be better in my situation?
Rowing I like more than cycling. But it's more expensive.
The bike looks smaller.
I forgot to mention, It is mandatory that I have a quiet machine, no squeaks , no sounds... never ever,
thank you for your help....