For the 3x3, those numbers seem good targets to work with. You need to set a time-frame too in order to have something to work towards.
Any target IMO should be specific, be attainable (but a struggle) and should have a time-frame attached.
As long as you are increasing the total load during loading phase (i.e. weight x reps x sets), it doesn't really matter how you do it. Some people like to increase the weight and keep the reps constant, others like to increase reps and keep weight constant. MOST loading programs using increasing of weight, but there are very effective russian programs out there which keep to a constant training weight and increase reps per set (starting at 6 sets of 3 on week 1, ending at 6 sets of 6 week 4).
It is usually easier to increase the weight by a small amount as it translates to smaller increases in total load. Because going from (for example) 100kg for 3 to 100kg for 4 is a total load increase of 100kg (300kg to 400kg). However, going from 100kg for 3 to 105kg for 3 is only a total load increase of 15kg (300kg to 315kg). Obviously with the weight loading then, it's easier to load by smaller amounts, which may or may not be preferable depending on how you like to load. Some like to load conservatively, others like to start off much lighter and load more aggressively.
Try it both ways and see which you prefer
