Ah got you.
This was what I was looking at which suggests that different sized bars can be used.
I figured ~3ft between posts would give enough space in between.
I finally treated myself to some new coloured bumper plates, I've been after some for a while and managed to get a decent discount so thought I'd go for it. They turned up today for me to find out that one of the 20kgs is a completely different shade of blue to the other! My OCD can't cope!
I have that rack - used it initially with a 5ft standard barbell which has 96cm between the sleeves
fine for squats altho managed to hit my funny bone on the spotters going down once since they're so close!
for bench press only thing you can do is close grip because again the spotters are too close together, or you could use the bench at the other side but then you don't get the benefit of the spotters