If u got the money then can go for 1.3 YRV .. Coz the halfcut price around rm5k-rm7.
Not really worth to put a 1.3YRV unless u got guts to mod and also got big bucks.
Eventhoe ur is HC-C (1.3)cc but that is not a big question about the approval.
Dont worry about the approval.I got friends that already converted to 1.0T int thier aura and got approve by the puspakom and the JPJ.
The most important to get approval is :
1.The document when u but the halfcut such as (Custom form and the resit you buy from a halfcut shop)as it got the engine number and etc.
2.Done the convertion properly.
3.Disc Brake have to Kaw kaw kawtim.
Dont worry, got money can go for the 1.0T and u want easy ride can go for 1.3 HC-E.