Replacing the lower is where you'll find the greatest handling improvement. TTR400 has a great swap in option for that. If you want the upper for cosmetics, then there are a wide variety of options. Getting one with the correct drop down is key for keeping stock geometry...unless you just get a super thick upper that lets you slide the forks to whatever position you want. I believe that an upper that is similar to stock will be pricier than your budget if you get the lower too.
Sorry I should have clarified, I'm asking more for repair than upgrade
The bike I purchased came with cracked upper triples, a common issue from what I understand. For that reason I wanted to see if people here have found better alternative to different stock units, such as swaps from other similar vintage hondas etc. I will look for TTR400's stuff, strange that I haven't seen it yet!
Edit: A correctly worded google search quickly brought me to his website... wow