If you are looking for a good review website for all Sony lens check out Dyxum.com they have a database dedicated to the Alpha mount. The best portrait lens would be primes and the 50 1.4 or 85 1.4 or 135 1.8 would be of choice. Although the 135 on the APC x1.5 sensor would be a bit long . I myself use the 50mm 1.4 or carl Zeiss 24-70 but this is expensive. The SONY SAL-1855 18-55 mm f/3.5-5.6 I believe is a kit lens aswell. if you are looking for a zoom you could also look for a faster lens such as the 17-50 F 2.8 Tamron. which gets good reports and is a good all round lens I had this for a time before I got the Carl Zeiss.
If you are looking for a cheap alternative I think I still have the Sony Kit lens the 18-70 – I think or it may be the 18-55 that I could sell you for a reasonable price as it is not used.
Brian – I was at the races too and I didn’t get any shots like that. They look great – can you give any tips as I have just started photography myself.