"We have identified our targets," said Sousa.
"We know what we want and if it's possible to get them in January I will be happy, but if they don't come I am happy with the players I have and happy to work with them.
"I want to have the opportunity to play with different systems and give us the possibility to play in different ways."
Rangers certainly lacked quality against a Watford side that defended well and almost snatched a late winner when Hornets midfielder Lee Williamson rattled the post with a free-kick.
"I'm a little bit disappointed with the first half. We conceded about 25 or 30 minutes to Watford," Sousa admitted.
"At half-time we made some adjustments and the team then began to control the game and make some chances. Sometimes a team just needs to have that killer instinct.
"I made a lot of changes because we had two games in two days and I have faith in my squad. I didn't want to risk some important players getting injured."
He added: "I am happy that from January the number of games we play is reduced to about one a week. That gives me more time to work on the training ground.
"A man is an animal of habit. If you train with high intensity then when the players are on the pitch they can deal with problems better."
Watford boss Brendan Rodgers was delighted to see his team bounce back from their 4-2 home defeat against Bristol City on Boxing Day.
Rodgers said: "I was really pleased. I thought we were terrific - especially in the first half.
"It was a big disappointment against Bristol City. We reflected on that game afterwards and I felt then that we would go on to have a good performance here.
"We came to a difficult place to play and I felt we were very good. The second half was a bit more even but a point was still the least we deserved.
"It was very important that we kept a clean sheet. We're the fourth highest scorers in the division but if you look at the defensive side, that's not been so good.
"If we're going to aspire to be better then we have to defend better as a team, and today we did very well.
"Anyone who has watched us recently will see there has been an improvement."