Thanks for this thread I just ordered.

Will use an impact driver to remove the flywheel with the puller so i don't have to lock the crank.

Local KTM Dealer Sydney
KTM sprag clutch 58440026000 $137aud

Af1
Qty Item Description Sub Total
1 AP0650341 OEM Aprilia Gasket -#0650341 (ex AP0650340) - $31.22
$31.22
1 PUMP08074 Aprilia 1000cc V990 Flywheel Puller - $14.99
$14.99
1 AP0659123 OEM Aprilia Sprag Clutch Hsng (Part 1/3) -0659123 - $166.02
$166.02
1 2R000113 OEM Aprilia Sprag Clutch Gear (Part 3/3) -2R000113 - $81.65
$81.65
Sub Total: $293.88
Shipping: $50.00
Insurance: $5.00
Tax: $0.00
*Adjustment: $0.00
Total: $348.88

Other tools to order
Locktite 648
+$21 ebay 50ml
Locktite 243
+$14 bunnings

14mm hex key
2-3ft breaker bar
Various smaller Allen keys (4,5,6).
small hose clamps
Fresh Oil 15w50
$90
Oil Filter
$20
plumbers torch
$35 supercheap
digital calipers
$31 supercheap

Works out to cost around $800 AUD for parts and all tools, with the consideration you already own an impact driver and socket set.