pella vinyl slider-need handle,latch assembly, lock cylinder and keys

It's very difficult to identify patio door hardware without the original parts on hand as a reference. That said, your door seems to be a pretty typical make so I do have a few educated guesses.

For the handle, see our 82-030B handle set. This has a 3-15/16" installation hole center spacing and an offset key lock. The hole pattern for your old handle appears to match this product but you should look it over just to be safe. This is available in white, black, and beige.

For the mortise, see our 82-218 (sold separately). This will also come down to size and hole spacing. I'll share a diagram below for both products that you can use as a reference. Note that in the case of the 82-218, it's made to be a tight fit; when you install it, you may feel like it's too big to fit in the hole, but that's by design. The trick is to put it in at an angle. I'll also share an installation video that you may find helpful.

Ultimately, without the original hardware as a reference, these are just guesses. You will need to make the final determination yourself as to whether these are worth considering.

Dimensions for 82-030B

Dimensions for 82-030B

Opposite side view 82-218

Profile view of 82-218