The only aftermarket UCAs that I know about that give greater coil nucket clearance are SPC, Total Chaos, and PRG. If you're really on a budget you could look to see where it's making contact to see if you can just trim the lip of the coil bucket.
You can add a bump stop to the stock UCA and soften the blow. UCA bump stop | Nissan Frontier Forum (clubfrontier.org)
The OE UCA contact the CB at the top. You would essentially need to cut out over half of the bucket (not just the lip) to avoid contact. But then you would not have a bucket.
I believe the PRG and TC UCAs both a built in bumpstop that will hit the bucket and decrease potential droop. The ball joints on the SPCs will just barely rub the lip of the bucket, depending on your alignment specs, but that can be taken care of with a small trip of the bucket itself. I knocked it out in about 5 minutes per side with a Dremel.
First gen PRG and the Total Chaos UCA are the only ones that have the bump stop. The new PRG does not, leaving the TC as the sole aftermarket UCA with the stop. Generally a stop is not needed as the internal stop in the front shock is what limits down travel. But once you add a spacer to the top of the shock then the UCA hits the CB before the internal stop does.
Though the internal stop is generally "good enough" to handle the suspension topping out, I have seen some shocks on Frontiers/X come apart from from this. This is the reason why I run a TC UCA.
Some e-bay spacers have a built in bump stop. NEver ran these, but thought it was a good idea.