Yeah, 1st-gen SV650 was great, still very popular on track. Actual weight was around 420-lbs though and gained more and more weight with each generation adding EFI and ABS. For that heft, you can use CBR600RR or R6 for tonnes more power.
Looks like hot ticket for 400 track bike is the Norton Ninja 400 that Rocco's been using for past couple years. Weighs in at 310-lbs and +15% more power.
https://www.cyclenews.com/2018/10/ar...aki-ninja-400/ . Rocco's a second faster than me at Laguna Seca on my CBR600RR and 9s faster than Ninja 250. Rocco raced AFM couple years ago, and won everything he entered. Would've placed in open and FP classes as well! And he's such a nice young man!