Marrying a chaste woman after committing zina

Q: I got into a debate with a person who has quoted from the Quraan about the topic on fornication. She stated that according to her understanding of the verses, a fornicator, even if they have repented cannot marry a pure person and if they do then the nikkah will not be valid. I debated that Allah Ta'ala forgives the sincere repenter so how can they be punished if they go on to marry a virgin etc. Please shed some light, was I right in my reply?

Paying zakaat on behalf of one's wife

Q: One year ago I got married. My wife was gifted with gold from her parents and my parents too. The gold qualifies the "nisab" amount. She is a domestic wife. First I planned to pay zakaat on the the gold in a lumpsum after one year. But being a salaried person I could not do it as per my planning. Now I intend to pay a certain portion of zakaat from my salary each month. Please guide me on how should I calculate zakaat. For example on completion of the first year, the rate of gold was different from now.