"Install them my self..." Not absolutely positive, but I recall the one guy that installed new fork springs sometime last year said that it is a pain and requires a special Triumph tool.
I've never bottomed out the front so the only reason I'd change the springs is for better performance. I don't know if it's really worth the expense and efforts when the front suspension works mighty fine as-is, certainly a ton better than the stock rear suspension. I'll be interested in hearing what you have to say about the new springs' performance characteristics.