Absolutely sell. Stocks should be used for an investment horizon of many years. Sell now, don't worry about year-end dividends. The stock price builds in how close dividends are, and drops when they are paid out. There's no benefit to trying to time that. Don't try to time the market. Just because things are going well now doesn't mean that will continue.
The most common recommendation would be to consider short-term bonds or time/term deposits. You want an instrument that you know won't fluctuate much since you know you will need to access this money in the near future.
The other option would be to look at REITs. They will fluxuate more, but should be correlated with the price of the house you are going to buy. So if real-estate prices go up, the increase in REIT value should help compensate for a higher purchase price. If they go down, you will lose some REIT value, but you should be able to get the house at a better price.
