My preference would be holding normal SPY and hedge the overweighted NASDAQ stocks with short NQ futures. In this way you only need to rebalance the NQ futures which benefits from 60/40 rule with better tax rate.
It is probably easier to just buy RSP and then buy virtually any 'market' or tech etf/mutual fund to round up the top 10-20% weighting as you want it. The reason I say any will do is that there is little difference in the holdings of most of the etfs and funds.