For 1/8 first bike try the kyosho, very easy to drive. Z201 need sometime to get use to but is much faster.
For 1/5 first bike try the SB5 or NF 509 standard. Both very easy to drive. BTW: the tires come with both kit are useless.... Get the PMT 200 or NF soft compound. Much better. ;)
ya, go to Jordan and see see first. Lot of kyosho there. For 1/8 use 1/18 motor and ESC, so not expensive. For 1/5 use 1/10 touring ESC and motors. The bikes, kyosho should be around 600, SB5 and NF around 2000, Z201 around 4000hkd.